In moderate climate zones, utility meters, particularly water meters, are located in subsurface ground enclosures in areas near residences or other dwellings. Such enclosures are referred to as “pits.” In these systems, a transmitter or transceiver, and an associated antenna, are enclosed in one or more sealed enclosures which are located in a larger pit for the water meter. In exemplary embodiments of these subsurface ground enclosures, the antenna is disposed in an upper compartment and the electronics are installed in a lower compartment with a double seal between the two parts.
A primary issue concerning all remote meter systems, whether used in pit installations or elsewhere, is their resistance to weather, and to submersion in the event that the pit fills with water. Therefore, the invention provides a device that is very resistant to moisture conditions in its operating environment. Typically, the data storage device is powered by one or more batteries, which must also be contained in a sealed enclosure.
In another exemplary embodiment, a utility meter transmitter assembly has three vertically arranged compartments with a lowermost compartment receiving a flowable material, also known as a potting material, to seal some wire entry points. Potting material is typically injected through a port into the bottom compartment. A battery was encapsulated separately in a battery assembly that was inserted into a lower compartment from the bottom. In these embodiments, the housing for the electronics is provided by a tube and the encapsulating material is injected through a bottom opening to encapsulate the electronic circuit board and the battery. The embodiment may further include a bracket for mounting components, such as the electronic circuit board, in a subsurface ground enclosure.
The potting material, providing protection for the electronic circuit board and other components to provide improved field service life of the product in a submerged environment. However, encapsulating an antenna in the potting material has been shown to have a negative impact on the radiated performance. Accordingly, utility meter transmitter assemblies generally have all components except the antenna and matching circuit encapsulated in the potting material. Traditionally, to avoiding encapsulating the antenna, assemblies are configured to include multiple circuit board assemblies, one for the primary circuitry and the second for a board mount antenna. The two circuit board configurations typically include a wired connection between the boards, multiple mounting components, etc.
The present invention provides an improved system and method of encapsulation and an improved sealed transmitter assembly for installation in a subsurface ground enclosure. As with other electronic devices, there is a desire to make the devices less prone to failure, less expensive to manufacture, and easier to service in the field.